Isolating muscles is so last year. Unless you’re rehabbing from an injury or working to strengthen a weaker part of your body, the rule of thumb should be to work as many muscles as possible with each exercise (while of course maintaining good form). The more muscles you can incorporate into each set, the more effective and efficient your workout will be.

You don’t need more time to work out; you just need more intensity. By swapping these five simple exercises you can maximize your effort and calorie burn while minimizing your time spent at the gym.

Squats instead of leg press machine

While a leg press is good for isolating your quads, it leaves something to be desired as a total-body exercise. The truth is you have to add so much more weight on a leg press machine to get the same effect that squatting vertically would have. And whereas the leg press includes little to no stabilizer muscle involvement (because the machine gives you total upper body support), squatting forces you to recruit those stabilizer muscles groups in order to complete each rep. That is, your hip adductors (inner thighs) to keep your knees spaced shoulder width apart, as well as your ab muscles to hold your torso in place as the knees bend. Talk about a full body exercise. Don’t forget to keep the knees right on top of the heels as you squat down—less pressure on the joints and you’ll really feel those hamstrings and glutes fire.

RELATED: 18 Moves to Tone Your Butt, Thighs, and Legs

Plank on a BOSU ball instead of crunches

In terms of overall total body effectiveness, we all know that the plank is superior to the crunch. By holding your entire body in an isometric contraction you’re strengthening everything from your abs and glutes, to your legs, back, and chest. But we’re cranking it up a little further. Adding some sort of balancing factor to your plank—in this case a BOSU ball—will have your whole body, especially your core, feeling the burn in no time. Simply place your forearms on the rounded side while you do your plank. You can also try them with your arms on the flat side. Once you master holding your BOSU ball plank for at least 30 seconds, start adding in some variations—slow mountain climbers and then adding a twist to the opposite side as you bring the knee into the chest are just a few to get your mind working. Any variation after that is fair game. Get creative!

RELATED: 20 Ways to Do a Plank

Pull ups instead of bicep curls

Despite popular opinion, a pull up is a much more effective way of targeting those guns than a typical curl would be. Plus, with a pull up, you’re working your entire upper body and engaging your core muscles too. The key is intensity. You can’t cheat a pull up; you either got it or you don’t. And don’t get discouraged if you can only muster one or two to start, know that you’re still exhausting your muscles and therefore building strength. If the thought of even one seems daunting, try wrapping a resistance band around the bar and hook your feet (or bent knees) into it for some assistance getting up. Then, once you become more proficient you can take the band away and start to add more repetitions.

RELATED: 10-Minute Workout for Defined Arms

VersaClimber instead of the bike

If you’re one of those people who loves to sit on the bike and occupy your upper body with a book or magazine while your lower body does all the work, listen up. Cardio success is not about the number of calories burned during your 45-minute session. It’s about elevating your heart rate enough for a prolonged period of time (about 20 minutes at 80% or higher) to achieve the “afterburn” effect, boosting your metabolism so you continue to burn additional calories throughout that day and the next. The VersaClimber is a great option because it incorporates upper and lower body movements at the same time, which not only keeps you engaged in the workout but also means you can cut your time spent on the machine in half. So, give it a try. In addition to preventing boredom, switching up your cardio routine will keep your body guessing and you on track to achieving your fitness goals. (Try this VersaClimber workout.)

Dumbbell bench instead of traditional bench press

Contrary to popular belief, the bench press is not the best move for the upper body. While it may do a good job of isolating a few specific muscles, using two dumbbells instead of the traditional bar will increase your range of motion and recruit more muscles in the shoulders and back as well. Not only that, but you can add some core work into the equation by alternating arms one at a time to challenge your balance and force those abs to join the party. If you really want to kick it up a notch, try switching out the bench for a Swiss Ball and get some more stabilizers involved!

Looking for more ways to enhance your workout? Try 5 Upgrades to Your Favorite Body Weight Moves and 7 Workout Habits You Should Drop Now.

Jennifer Cohen is a leading fitness authority, TV personality, entrepreneur and best-selling author of the new book, Strong is the New Skinny. With her signature, straight-talking approach to wellness, Jennifer was the featured trainer on The CW’s Shedding for the Wedding, mentoring the contestants’ to lose hundreds of pounds before their big day, and she appears regularly on NBC’s Today Show, Extra, The Doctors and Good Morning America. Connect with Jennifer on Facebook, Twitter, G+ and on Pinterest.